System and method for monitoring frequency and intensity of movement by a recumbent subject

ABSTRACT

An integrated subject monitoring system facilitates measurement, collection and analysis of data pertaining to frequency and intensity of movement by a recumbent subject. The system includes a network-coupled computer and sensors placed in a bed or other resting surface of the subject. Parameter data is obtained primarily passively, without the cooperation or active participation of the subject. Subject parameters can be continuously monitored, sampled and recorded. Captured values then can be compared to initial baseline values for a measured parameter as well as to the trend the parameter of that subject. Readings falling outside the boundaries can trigger a signal to be sent to an appropriate party. The system preferably further includes a location monitoring or tracking subsystem for determining a subject&#39;s location within a defined space. Location data from the subsystem can be used to identify the subject being measured by the sensors in the bed.

RELATED APPLICATION DATA

This application is a divisional of and claims priority to U.S. Ser. No.09/706,327, filed Nov. 3, 2000, now U.S. Pat. No. 6,524,239 which inturn claimed priority to provisional U.S. Ser. No. 60/163,709, filedNov. 5, 1999.

BACKGROUND OF THE INVENTION

The present invention relates generally to health monitoringapparatuses, and more specifically to a system for non-intrusivelymonitoring the health status of a subject.

A subject's health status is typically evaluated by reference to aplurality of vital signs, such as pulse and respiration rates,temperature, blood oxygen saturation, weight and body hydration.Additional considerations include observations as to subject appearanceand movement. These latter factors are also indicative of the subject'smental health, e.g., cognitive ability. Other cues are the degree ofanimation, compliance with responsibilities such as self-medication,forgetfulness as to whereabouts or activities, and the like.

In traditional residential care facilities, these indices are measuredand observed by caregivers. While measurements are generally recorded, aportion of the observations is retained only in the institution'smemory. This fact is especially true in the case of cognitive healthcues.

Retention of caregiving personnel serves the critical role of logicallypreserving of the meaning and functionality of health data. Interactingwith a patient over a period of time, a caregiver learns a great dealabout the habits and individual vital sign trends of that patient. Thelarge volumes of observed data provide evidence to support thediagnostic requirements of residential care professionals. Raw datapertaining to a subject's health status functions to provide the contextin which present parameter values can be assessed.

With caregiver turnover, this context is minimized or lost unless theobserved information has been reduced to writing for the new personnel.Typically, a fraction of the total observed data is so recorded.Sub-clinical observations are frequently useful in assessing subjecthealth status, especially cognitive abilities. These data includesubject demeanor, alertness, regularity and subject mobility. The commondenominator is that these characteristics change gradually. They aretherefore less noticeable to new personnel, who have not observed thesubject over time and are not familiar with these characteristics.

Short institutional memory produces a lengthening of the time beforecaregivers or other health professionals become cognizant of a slowdecline in a subject's health status. The delay in appreciating adecline causes a corresponding delay in responding to healthdeterioration of the subject. As a result, the subject suffers adepression in the quality of health care received.

Bed sensors, similar to those described herein, are known (e.g., U.S.Pat. Nos. 5,640,145; 4,633,237; and 5,554,835. However, these prior artsensors heretofore have been used to detect presence or absence of asubject. As well, U.S. Pat. No. 5,235,319 discloses a capacitive bedsensor for differentiating subject movement in a bed from subjectdeparture from the bed, to remove inappropriate departure alerts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of the system according to the presentinvention.

FIG. 2 is a block diagram of the physiological monitoring subsystem ofthe system of FIG. 1.

FIG. 3 is a block diagram of the cognitive monitoring subsystem of thesystem of FIG. 1.

FIG. 4 is a block diagram of a movement monitoring system suitable tomonitor a recumbent subject.

FIG. 5A is a diagram of a resting surface having a plurality of forcesensors coupled thereto.

FIG. 5B is a diagram of a resting surface with a plurality of forcesensors positioned therein.

FIG. 6 is a diagram of a representative living area in which the presentmovement monitoring system can be disposed.

DETAILED DESCRIPTION

The present invention is an integrated subject monitoring system. Thesystem facilitates measurement, collection and analysis of objective andsubjective data pertaining to the physiological and behavioral healthstatus of a subject.

The system includes a network with a computer, data storage device anddata analysis means. Raw data and analyses can thereby be accessed bythe subject or resident caregiver. Additionally, this information can beremotely accessed by a health care provider, family member or otherauthorized entity.

Further included are subsystems, operative to obtain measurements of asubject's physiological or behavioral/cognitive parameters within adefined multi-room space. Parameter data is measured primarily passivelyand without the intentional cooperation of the subject. According tothis aspect of the present invention, the majority of the healthparameter data can be obtained without relying upon the subject toremember or to actively participate in data acquisition.

The system of the present invention provides for prompts to be given asubject, to promote activities such as medication compliance,continence, and interactive parameter measurement. These prompts serveboth to increase compliance as well as to encourage and reinforceroutine behaviors and activities.

Additionally, the system comprises a subsystem to monitor subjectlocation within the defined space and the curtilage thereof. Thismonitoring is performed without direct human supervision. Upon therequest of a user, the system provides real-time information concerningthe location of a monitored subject. Analyzed as a function of time,positional measurements provide locomotive information about thesubject.

Further, control of ambient/environmental conditions is effected throughthe system of the present invention. Environmental inputs by a subjectare recorded, enabling a system user to assess physical as well ascognitive aspects of the subject.

Another aspect of the present invention is a method of monitoring thephysiological and behavioral/cognitive health status of an ambulatorysubject, wherein the monitoring is primarily accomplished passively andwithout the active cooperation of the subject.

Indicia of physical and mental health are monitored by the system. Aninitial baseline is established for each of the measured parameters.Subject parameters are continuously sampled and recorded. Each readingis compared to the baseline as well as to the trend for the parameter ofthat subject. A user inputs parameter boundaries, which then serve aspredetermined thresholds for that parameter. When a reading fallsoutside the boundaries, the system triggers a signal to be sent to anappropriate party.

Using chronological identifiers, the system can also determine physicalor behavioral anomalies as a function of time. A user can set the systemto transmit an alert when two or more parameter deviations occurcontemporaneously. Thus, the system can be instructed that a combinationof discrete deviations is of sufficient concern that warning message ismerited, even when any one of the deviations would not trigger awarning.

As used herein, certain terms are meant to convey specific meanings. Inthe taking of a measurement by a sensor, “passive” or “irrespective ofsubject cooperation” means that the parameter measurement occurs withoutconscious collaboration on the part of the subject to accomplish ameasurement. Lack of cooperation means that, for those health parametersmeasured passively, the subject need not even be aware that a sensor ispresent or that a measurement is being taken.

The term “ambulatory” means that the subject is capable of perambulationwithout personal assistance; i.e., the subject is not bedridden.

A cognitive parameter is a parameter indicative of the mental process orfaculty of a subject, including abilities such as awareness, perception,reasoning, memory and judgment. A behavioral parameter refers to anindication in the form of an action of a subject, as well as a reactionin response to an external or internal stimulus. As used hereinafter,the term “cognitive” encompasses both cognitive as well as behavioralcues.

A first aspect of the present invention is a health monitoring system,being operative to monitor physiological and behavioral/cognitiveindices of a subject. As shown in FIG. 1, the system comprises acomputer 102 coupled to a network, the network being accessible by atleast one remote node 108. The computer is further coupled to aplurality of monitoring systems, described in detail infra.

The network comprises a computer 102 with a data storage device 104,wherein the collected measurement data resides. The computer isprogrammed to collect information in the form of measurements, associatesubject identity codes (SIC) therewith, further associate chronologicalidentifiers (i.e., a time stamp) where appropriate, and store the datarecord. Coupled to the computer, a data analysis means 106 is used toanalyze the stored data records. The types of analyses are discussed inmore detail, infra.

System outputs comprise health status and care reports 110 and billingsummaries 112. These reports can be delivered via conventional methodsor accessed via one of the remote nodes 108.

Caregivers are responsible for recording via a remote network node 108the types of services provided to each subject. In traditionalresidential care settings, caregivers must hand-write notes. The systemaccording to the present invention enables caregivers to log furnishedservices via a touch screen, palmtop digital assistant, keyboard, orother input device. This computerized process decreases the amount oftime caregivers spend writing down notes and maximizes the time that canbe devoted to the provision of care services.

As needed, a caregiver also inputs general observations pertaining to asubject. As well, a subject can enter comments and non-observablecomplaints and symptoms. These comments are entered into one of aplurality of terminals 108 distributed throughout the defined space. Theterminals can also have voice recognition software or optical characterrecognition scanners so that caregivers can enter information withouttyping. A person skilled in the art will also recognize other waysinformation can be entered into the system.

As with other measurements, entered data is associated with achronological identifier and stored. This data point can be used incaregiving assessments as well as summaries 112. Summaries can includebilling statements, care reports and other matters, generated anddistributed either online or through traditional avenues.

Subject location and movement, physiological, cognitive parameters aremonitored by subsystems of the present invention. These subsystemsgather data from which the health status of the subject can bedetermined. The data-gathering sensors report information to the system,which then identifies the measured subject using the tracking subsystemdata. The system thereby can associate a subject identification code(SIC) and a chronological identifier to the parameter datum.

A first monitoring subsystem is a tracking subsystem 120, useful tomonitor the location and mobility of a subject. Each subject carries asmall radio frequency (RF), infrared (IR), or other wireless personaltransmitter, transmitting a code unique to that subject. A subset of thesensors is RF-, IR-, or other wireless receivers, distributed throughoutthe defined space and its curtilage. As the subject moves about in thisregion, sensors detect subject presence and signal the system of thesubject's location.

The personal transmitters act as identification badges and serve as keysto accessible rooms. Each personal transmitter further possesses a“panic button”, enabling the subject to issue an emergency call to thesystem in the event immediate attention is required. So activated, thepersonal transmitter notifies the system of both the identity and exactlocation within the facility of the subject. This information shortensreaction time and permits a customized response.

By the association of chronological identifiers to these signals, thesystem can calculate locomotion data informative as to a subject'smobility, i.e., walking speed. Further, overall distance traveled can beassessed, both to evaluate the level of the subject's activity andexercise as well as to detect any decline in locomotive ability.

If a subject exceeds predetermined boundaries, such as entering anoff-limits room, or walking beyond a certain radius from the facility,the system can page or otherwise alert an appropriate party, i.e., acaregiver. In such an instance, a caregiver can check a network terminalto learn the subject's exact location. A caregiver in one location canthereby respond instantaneously to any of a plurality of ambulatorysubjects. The system maintains continuous monitoring as subjects movefreely throughout the space. Subjects also feel a sense of freedom,moving about the area ad libitum and unaccompanied, without reducingpersonal safety.

Direct monitoring of a subject is accomplished by a physiologicalmonitoring subsystem 130 and a cognitive monitoring subsystem 140. Eachof these subsystems comprises at least one sensor coupled to thenetworked computer. Preferably, a plurality of sensors are distributedthroughout the area in which the subject can move, such that thechronological gap between any two consecutive parameter samplings isminimized, regardless of the location of the subject within the area.

Input in the form of data signals is received from a plurality ofsensors and from remote network nodes. Both the sensors and the remotenodes are distributed throughout the defined multi-room space. For eachsensor, a coupled signal generator generates a digital signalcorresponding to the obtained measurement. The signal is thentransmitted to the networked computer, associated with a subjectidentification code, and then stored and analyzed.

The tracking subsystem makes possible the use of promiscuous sensors,which measure parameters without regard for the identity of themonitored subject. By reviewing subject identities and locations fromthe tracking subsystem, the system can determine the identity of thesubject sufficiently proximate to the signaling sensor for measurementto be achieved. That subject's SIC is then associated with the parametermeasurement signal from the sensor.

Turning now to FIG. 2, the physiological monitoring subsystem comprisessensors to measure vital signs and other health parameters of a subject.These parameters are preferably blood pressure 200, pulse 210,temperature 220, weight 230, oximetry data 240, sleeplessness 250,subject location 260, respiration rate 270, body hydration 280, andexcretion/elimination data 290.

A subset of the plurality of sensors measures parameters with the activecollaboration of the subject. These sensors comprise a cuff to measureblood pressure 200, an oximetry 240 device, a respiration 270 monitorand a remote node 108, preferably a computer terminal, at which thesubject can enter subjective inputs. A person skilled in the art willalso recognize other sensors which can measure parameters with theactive consent of the subject. Collaborative sensors can be stationarydevices; alternatively, a telemetric sensor can be worn by the subjectand the data transmitted from it to a proximate receiver. Distributionof receivers throughout the defined space permits the subject to movetherethrough with uninterrupted data acquisition and transmission by thesystem.

In contrast to the subset of sensors discussed, supra, a second subsetof the system's sensors obtain parameter measurements irrespective ofsubject cooperation. More specifically, those sensors are operative tomeasure physiological or cognitive parameters as the subject engages ineveryday activities generally unrelated to health monitoring. Thesensors comprise many types, including thermocouples, infrared andmotion sensors, conductive elements, force sensors and other transducingsensors. A person skilled in the art will also recognize other sensorsthat can be used.

As an example, a load sensor can be embedded in a chair in the subject'spersonal living space, enabling body weight 240 to be measured wheneverthe subject sits in the chair. In this manner, the subject need not usea conventional scale, consciously report the weight reading, or even beaware that the load sensor resides in the chair. The unrelated act ofsitting in the chair, e.g., to rest, read or watch television, issufficient to enable the system to obtain a body weight measurement.

Weight 230 is detected via force sensors positioned to measure z-axisforce applications to the subject's sleeping surface. These sensors thusenable determination of the mass of an object or person resting on thesurface. Sleeplessness 250 can be simultaneously measured usingadditional sensors to detect lateral motion of the surface owing tomovement of the subject. Occurring during the night, this movement isindicative of subject restlessness and can be utilized to perceive andquantify sleep difficulties or disorders.

By contrast to prior art bed sensor devices, the present system—formonitoring frequency and intensity of movement by a subject—divergesfrom the above conventional bed sensor technology applications bydetecting and analyzing differential forces. Of course, the presentsystem can be combined with a subject presence/absence detector ifdesired.

As depicted in FIGS. 5A and 5B, a system for monitoring frequency andintensity of movement by a subject during sleep includes a sleepingsurface 20 upon which the subject rests. The resting surface 20 can be abed, such as the type found in households, a hospital bed, or other kindof bed. Alternatively, other resting and/or sleeping surfaces can beemployed, including a reclining chair or other furniture providing aresting surface 20 for a subject.

Coupled to the resting surface 20 is a plurality of force sensors 22.Each force sensor 22 is structured to develop a potential correspondingto an application of force upon the resting surface 20 by the subject.

The force sensors 22 of the plurality of force sensors are positioned soas to detect a force applied to the resting surface 20 along a vertical(or Z-) axis and, preferably along a Z-axis, X-axis and/or Y-axis. Theseforce sensors 22 can be disposed underneath the legs or feet of astructure having a resting surface 20 or, alternatively, the forcesensors 22 can be embedded in the structure of the resting surface 20.

The system preferably also includes an analysis means 106 for comparingdata signals from the plurality of force sensors 22. The analysis means106 can determine X-, Y- and Z-axis movement of the subject while uponthe sleeping surface by analysis of potentials communicated from theplurality of force sensors activated by the patient's body.

A method for monitoring frequency and intensity of movement by arecumbent subject includes providing a surface 20 upon which the subjectrests, the resting surface having coupled thereto a plurality of forcesensors 22 structured to develop a potential corresponding to anapplication of force to that force sensor 22. The provided restingsurface 20 preferably has the plurality of force sensors 22 spatiallypositioned such that a force applied to the sleeping surface isdifferentially sensed by each member of the plurality of force sensors.

An initial force can be that applied by placement of a subject upon theresting surface 20. Alternatively, the system can be initialized with asubject already in place on the resting surface 20. Such variations donot affect the function of the system as described herein.

Changes in force, exerted upon the resting surface 20 by the subject asa result of subject movement, are differentially sensing by each of theplurality of force sensors 22. Subject movement can involve departurefrom the resting surface 20. In a preferred case, such changes in forcecorrespond to tossing and turning of the subject, e.g., rolling,movement of the limbs, curling or uncurling of the body, movement ofblankets or other bed linens by the subject, and the like.

Generated potentials, associated in one alternative embodiment withchronological identifiers, can be communicated as movement data to adata analysis means 106 for analysis, including data analysis todiscriminate among x-, y- and z-axis movement of the subject while uponthe surface.

Data analysis can include producing trend data using the stored signalsand associated chronological identifiers. Such trend data can be used todetermine abnormalities in the subject's sleep patterns and is useful indetecting changes in physical and/or mental health of the subject. Ahistogram also can be produced using the stored potentials andassociated chronological identifiers.

An alternative embodiment of the movement monitoring system suitable tomonitor a subject during sleep includes a resting apparatus 20structured to support the subject.

The apparatus 20 has a plurality of force sensors 22 coupled thereto andpositioned to facilitate development by a force sensor 22 of a potentialcorresponding to an application of force on the apparatus.

The force sensors 22 can be positioned so as to detect a force appliedto the apparatus 20 along a vertical axis, i.e. the Z-axis.

Force sensors 22 preferably are positioned to detect applications offorce applied to the apparatus 20 in any of the X-axis, Y-axis andZ-axis directions (FIG. 6). So arrayed, the force sensors 22 can developpotentials corresponding to subtle forces applied to the apparatus inthree dimensions.

A personal tracking subsystem 120 is structured to determine a subjectidentity from a detected identity signal corresponding to subjectidentity. The personal tracking subsystem 120 already has been describedabove.

A processor 10 with a data storage device 12 coupled thereto is providedto receive potentials from the plurality of force sensors 22 as well asthe subject identity signal.

Data analyzer 14 can associate the identity signal with the potentialsto form a data record for the identified subject.

The analyzer can use a plurality of potentials to discriminate among x-,y- and z-axis movement of the subject while upon the sleeping surface.

Monitoring frequency and intensity of movement by a recumbent subjectincludes providing a surface 20 upon which the subject rests, with aplurality of force sensors 22 coupled to the surface 20 and each forcesensor 22 structured to develop a potential corresponding to anapplication of force thereto.

Changes in force are differentially sensed by the plurality of forcesensors 22, such changes in force corresponding to movement of thesubject upon the surface.

The potentials can be communicated to a data analysis means 106 asmovement data for analysis to determine the subject's movements while onthe surface 20. Analysis further can include determining trend datausing the movement data and associated chronological identifiers, suchtrending being presentable to a user in the form of a histogram or otherdepiction.

In an alternative embodiment, chronological identifiers can beassociated with the potentials. This added data permits more refinedtrending and can be used to more efficaciously evaluate frequency andintensity of movement of the subject.

Use of force sensors 22 structured and/or arrayed to detect applicationsof force applied to the surface 20 in any of the X-axis, Y-axis andZ-axis directions (FIG. 6) enables discrimination of X-, Y- and Z-axismovement of the subject while upon the surface.

Examples of other sensor types and their deployment include a pluralityof sensors embedded in a toilet seat in a subject's living space. Duringa routine toileting event, these sensors can measure temperature, pulse,hydration and weight.

Temperature 220 and body hydration 280 can be measured by thermocouplesin the seat. A set of conductive elements, embedded in the toilet seat,measure body impedance during a routine toileting event. From thisimpedance data, both pulse and body hydration can be calculated. Thesecalculations are well-known in the art.

Bowel movement and urination 290 are monitored by sensors in the toiletseat and bowl. Thermocouples in the seat and bowl measure the subjecttemperature 220 and the temperature of the bowl contents, respectively.As well, force sensors provide weight 230 readings at the beginning andend of the toileting event. Changes, occurring during the toiletingevent, in subject weight and in the temperature of the bowl contents canbe used to calculate the fecal mass and/or urine volume of the event.The data also displays the subject's regularity in terms of frequencyand volume. When accumulated over time, this information is useful todetect changes in the subject's habits or abilities. These changes canbe due to physical problems or to declining mental faculties.

Similarly, force sensors, e.g., load cells, are employed elsewhere todetect the subject's weight 230. Force sensors are deployed under thelegs of the subject's bed, in the feet or casters of a chair in thesubject's living space, or in a toilet seat/footpad arrangement. Bodymass is appreciated when the subject rests on the article in which theforce sensors have been inserted.

Temperature 220 is also monitored with a thermal (infrared) camera,which scans a part of the subject's body such as the forehead. This scancan occur while the subject is engaging in any routine activity, i.e.,applying makeup in front of a mirror, using a computer terminal, orother activity in which the subject's head is predicted to be within thedefined zone of sensor measurement. From this scan, the systemdetermines the relative body temperature without physically contactingthe subject or interfering with the subject's normal activities.

The system according to the present invention further comprises acognitive monitoring subsystem 140, measuring indices of the mentalhealth of a subject. This health is specifically focused on theawareness, perception, reasoning, memory and judgment of the subject.The cognitive monitoring subsystem is show in FIG. 3.

These parameters are also measured primarily passively and withoutsubject cooperation. Some of the indicia are derived from interactivebehavior otherwise unrelated to the measuring of a cognitive parameter.

An example of the direct measurement of a cognitive parameter isobservation of medication compliance 310. Data is generated from amedication compliance device, provided to each self-medicating subject.The device includes a sensor to record opening and closing of themedicine cabinet door. Load cells are positioned beneath each medicinecontainer and are operative to record the mass of a container and itscontents. By controlling the size or shape of the containers, eachcontainer can be uniquely and consistently identified. The load cellsare sufficiently discriminating to discern when a pill or tablet hasbeen removed from a container, indicating that the patient has removedmedication corresponding to that container.

An incremental decline in medication compliance can be illustrative ofdeclining mental faculties. By recording compliance over a significantperiod of time, this slow deterioration in compliance can be noted by acaregiver or other health professional.

Indirectly, cognitive indicia are obtained by evaluating irregularitiesin subject behavior. Sudden changes in adjustment of environmentalcontrols or lighting 320 can also signify aberrant behavior. Failure tosubmit to routine, interactive parameter measurements, such as bloodpressure 200, are detected from the data generated by the physiologicalmonitoring subsystem 130. Variations in restroom

By the same token, eccentric movement, wandering and improper attemptsto enter personal living spaces of another subject are indicative offorgetfulness and confusion. The system can analyze mobility data 260 todetermine instances wherein the subject mistakenly tried to enteranother subject's room, wandered or repeatedly visited the toilet whennot necessary. By tracking mobility over time, a health professional canassess discrete wanderings in the context of the subject's normalroutine, as established over a period of time. Declines in cognitiveability are thereby more readily appreciated.

The subject is empowered to disable data acquisition relating to one ormore parameters, by deactivation of either a sensor in the subject'spersonal living space or of the subject's unique transmitter. In thelatter instance, the system is not stopped from acquiring themeasurement; the system is simply unable to associate a subjectidentification code with the value.

Deactivation by a subject of data collection for that subject can beinadvertent. Conversely, the subject can feel the need for greaterpersonal privacy, whether generally or to engage in an activity havingthe potential to trigger an alert. While the subject is free to disabledata collection, the deactivation event itself is duly recorded. Suchevents are noteworthy, as they can indicate a change in mental healthstatus or an intentional obstruction of proper system operation.

Redundancy is employed to maintain a continuous stream of data, even inthe face of changes in the subject's daily routine. Using bodytemperature as an example, thermocouples are embedded in the subject'stoilet seat as described. The thermal camera acquires temperature datain a different location. Thermocouples are also embedded in othereveryday objects in still other locations. Because sensors are embeddedwithin everyday objects, the sensor cannot obtain measurements when thearticle in which it is embedded breaks or is otherwise out of service.By using a plurality of sensors to measure a single parameter, thatparameter can be constantly monitored even if, for example, a specificwall-mounted sensor fails or the subject's toilet becomes temporarilyunusable.

The passive acquisition of physiological and behavioral measurementsensures greater compliance with data measurement and recordation thanoccurs in traditional residential care procedures. Long-termrecord-keeping permits a current measurement to be viewed in the contextof the patient's individual history for the given parameter. This“institutional memory” improves evaluation of the subject's healthstatus.

Deviations from the subject's normal values are also more rapidlybrought to the attention of an appropriate party, e.g., health careprovider, on-site caregiver, subject or other entity authorized toaccess the data. Lastly, the subject's daily activity and routine areimpacted much less than in traditional residential care facilities,where a patient must submit to a caregiver's measuring of parameters,i.e., temperature or pulse.

The sensors are coupled to the network via wired or wireless connection.Data transmission of signals to the data storage device is therebyenabled without regard for the type of sensor or coupling means for thatparticular sensor.

The system uses a variety of audible and visual cues to prompt subjectbehavior and compliance. For example, a simple chime or other tone canbe employed to signal meals. As a more relevant example to health andelder care, a colored or flashing light in the subject's medicinecabinet can be used to signal medication intake. A tone, synthesizedvoice or email message can be employed to signal the need for aparameter to be interactively measured. The system can turn on thesubject's room lights during the night to wake the subject and prompt atoilet visit to maintain continence. A tone can also be used both tosignal when a subject nears the limits of the monitored area and as amore general warning that the subject is about to leave the facilitygrounds. As is well-known with wireless paging technology, a vibrationor silent mode alert can be employed to provide the subject a greaterlevel of privacy. A person skilled in the art will also recognize othercues that can be used.

Output of the system according to the present invention comprisessummaries and request responses for each monitored subject. The outputsare tailored for each receiving party (e.g., subject, physician,caregiver; or subject's family member). Reports provide detail onsubject health over each reporting period. Data in these reportsincludes provided care services, described by frequency, type, and cost;types of activities in which the subject participated (again, byfrequency and type); and a movement report. These summaries providespecific health information and also convey a more generalrepresentation of the subject's quality of life and care in thefacility. Caregivers and administrative personnel are relieved of thetask of relating this information to physicians, family members, andothers. Thus freed from performing a number of administrative duties,caregivers can devote a greater portion of their time to the provisionof services and care of the subjects.

Remote access to data by off-premises persons facilitates the sharing ofsubjective and objective measurements, and transmits information in auser-friendly format through digital channels. Access by healthprofessional, family members and other off-premises persons is through anetwork connection. The subject controls access and the degree ofviewable information for each party desiring to view subject data.Subject data privacy is thereby assured with respect to each type ofviewer, i.e., physician, family member or other person permitted to viewsuch information.

It should be apparent that the system of the present invention can beapplied to subjects of various states of health. The system is mostefficacious when applied to fully ambulatory subjects but can be adaptedto monitor subjects requiring ambulatory assistance.

Another aspect of the present invention is a method of monitoringindicia of the health status of a subject. Monitoring is performed in apredominantly passive manner, without the cooperation of the monitoredsubject.

In residential care facilities, deviations from the standard parametervalues are significant and receive the attention of a caregiver orhealth care provider. As discussed, caregiver turnover reduces thefamiliarity of any one caregiver with the broad history of a particularpatient. The system of the present invention improves patient care byserving as the “institution”, compiling and retaining a detailed historyof all of the pertinent health parameter measurements of a subject.

A corollary feature of this role is to sooner detect large or frequentchanges in data patterns. By compiling a large body of informationdescribing a subject's health history in terms of certain parameters,the system readily detects variations in data patterns as they occur.The system can thereby immediately alert the proper party of thedeviation. To accomplish this goal, data is logged and analyzed forcomparison with against pre-established limits. When the parametermeasurement falls outside the pre-approved range of values, anotification is issued to the appropriate party for remedial action.

Prior to and during move-in to the facility, subjects complete differentprofiles, summarizing financial, health, system, and personalinformation. These assessments are stored by the system.

The health assessment will be the basis for a health care service plan.The system profile establishes health parameters and negotiated riskagreements, described in greater detail below. The personal assessmentis a list of several hundred questions that subjects complete to helpstaff quickly find commonalities with other subjects and staff, thesepersons having also completed the profile assessment. The profiles aremaintained in a database in the system's data storage device, such thatthey can be queried by caregivers, administrators and other authorizedparties.

The present invention permits the establishment of dynamic parameters inthree categories of subject health: vital signs, inputs/outputs, andbehavior and cognitive indices. These parameters are individualized andexplicit. They are formalized in a negotiated-risk agreement executed bythe elderly subject, physician, family, and caregiver. Negotiation bythese parties of parameters give subjects levels of independence andrisk-taking ability that neither affect facility liability exposure norjeopardize the personal safety of the subject. The parameters can beamended from time to time, according to changes in a subject's cognitiveand/or physical capabilities.

This negotiation also determines whom to notify when any one of a numberof events occurs. One such event is a subject parameter exceeding thepredetermined threshold. Alternatively, a number or particular group ofparameters can be out of compliance before an alert is warranted. Inanother example prompting an alert, a subject parameter can show a largepercentage change from one measurement to the next. By tracking movementin parallel with other parameters, the system can discern when a pulseor temperature increase is due to heightened activity rather than theresult of a health aberration.

The method comprises providing a networked monitoring system, asdescribed above. Generally, a plurality of detectors are positionedwithin the defined space, each of the plurality of detectors capable ofdetecting a physiological parameter of the subject. Examples ofphysiological parameters have been previously described and include, forexample, pulse 210 or weight 230.

Parameter values are then passively measured, without subjectcooperation or active participation in the measurement step. A signalcorresponding to the measured parameter value is generated andtransmitted to the data storage device. The measured parameter value isassociated with a subject identifier and, where applicable, achronological identifier.

In taking these initial parameter measurements, the system therebyestablishes a baseline value for each health component. Taken in tandemwith the parameter limits established at the outset, the baselineconstitutes the standard against which the system evaluates subsequentmeasurements.

Subsequent parameter trending establishes an ongoing history of thesubject's physical and mental health, as well as providing a context inwhich to evaluate current measurements. Specifically, normal trends canbe identified for each subject and parameter. In this way, normalfluctuations are more readily recognized and distinguished fromabnormalities requiring health care attention.

This institutional memory provides a fuller record of objective andsubjective observations regarding the subject. Against this tapestry,subtle deviations in vital signs, daily routine and cognitiveperformance are more accurately assessed and more promptly detected.

Occurrences calling for party signaling include instantaneousconduct-oriented events such as “panic” or emergency calls by subject orfacility staff, disabling of one or more sensors by a subject, ordeviations in one or more monitored health parameters.

Variations in parameter values are noted as they occur, with alertsgenerated according to response criteria defined by a system operator.The system permits the assignment of priorities to the variousparameters, as well as to the degree of deviation necessary before analert will be generated and sent.

For less critical parameters, variations are merely noted. On the otherhand, detection of a medically significant parameter aberration can beset to prompt an immediate notification event. Upon receiving anemergency call from a subject's personal transmitter—signifying thatimmediate attention is required—the system responds with appropriatecues to garner the attention of the proper party, including light, soundand pager signals.

The patient monitoring and tracking system and method of the presentinvention use real-time data collection and digital communication toimprove the health care and quality of life of subjects in assistedliving facilities, residential care facilities, adult foster care homes,and private residences serviced by community-based care.

The present invention is uniquely adapted to these care settings. Itdevelops, adapts, and integrates thermal infrared monitoring, sonicrecognition, radio frequency transmitters and other technologies. Thesetechnologies are combined with Internet-based communication networks tomonitor human health and provide behavioral cues to prolong subjectindependence. The monitoring system according to the present inventiongathers, logs, and transmits health-related data such as bodytemperature, oximetry, pulse, weight, hydration, blood pressure andmobility, doing so without interfering with subjects' normal activitiesor home environment. Ambient sensors control the heating, ventilationand air conditioning (HVAC) to suit subject needs.

The present invention differs from the traditional model of long-termcare by reducing the amount of risk faced by facilities, thereby freeingthem to fully experiment with and realize the potential of asubject-centered care model. In effect, the present invention shifts theparadigm of care back several generations, recalling a time when familymembers, country doctors, and others were closely in tune with anelderly person's history, condition, habits and preferences.

Features and Benefits

The system addresses the needs of at least five groups: subjectsreceiving health care; caregivers and care-giving facilities; thesubject's families; physicians; and researchers. These groups presentlydo without important, reliably-gathered health information in mostnon-institutional settings. As a result, personnel caring for an elderlyperson living alone or in a large facility are often unable toproactively diagnose and treat illnesses.

Moreover, conventional scenarios frequently limit the time and attentiongiven to any one subject. As well, staffing patterns in thesesettings—and the nature of operation of such institutions—often limit aresident subject's autonomy. Home health aides must visit severalpatients each day, restricting the amount of time devoted to dataacquisition at any one site. Residential facility caregivers cannotmonitor a large plurality of subjects simultaneously.

The system automatically records important physical and mental healthindicators. Caregivers, freed from paperwork needed to meet accounting,insurance, and legal requirements, can spend more time with subjects.Health care personnel also gain a better understanding of subject healthtrends and can engage in meaningful conversations about the type of careprovided. Staff can manually enter observations and other comments abouta subject's daily life into the computer via touch screens and othertechnology found throughout the facility.

Logistic concerns and legibility issues are thereby reduced. Automatedrecords also simplify billing and minimize problems associated with highcaregiver turnover rates. Administrative practices are therebysubstantially automated. As well, the care facility can receive subjectfeedback regarding quality of services, caregiving and physicalresources. Subject comments, entered into the system, can be employed toimprove the quality and efficiency of the facility.

In an elder care setting, the present invention grants subjects morecontrol over their daily decisions without sacrificing their safety.Subjects have freedom to take risks which otherwise would be prohibited.Historical data recorded by the system gives subjects the ability tomake informed choices about the type of care they receive. Dynamicrisk-autonomy health parameters and custom health summaries givesubjects incentives to improve their mental and physical well-being,thereby prolonging life and reducing health care costs. Prompts prolongsubject independence as cognitive ability changes.

For the families of monitored subjects, family members can be informedas to the specific types, quantity and subject-perceived quality ofhealth care services provided to the subject. Families receiving healthsummaries and billing breakdowns based on the information collected bythe computer. Families need not rely solely on generic billingstatements and the written notes of caregivers. The billing statementscan include subject comments concerning quality of health care services,caregivers and the facility's physical resources, informing familiesthereon in substantially real-time. In addition, family members can beadvised automatically of emergencies via real-time system-initiated datatransfer over the Internet, via telephone or pager.

Doctors and other authorized persons needing detailed records on subjecthealth have immediate access to necessary data via e-mail and theInternet. Trends for subject vital signs; system inputs and outputs;subject movement; frequency, variety and duration of activities; andother crucial information are accessed easily through the systemcomputer. Physicians do not have to rely on written logs that are oftenmaintained at the facility and frequently difficult to interpret. With aclearer understanding of health trends, physicians and others canprescribe treatment plans based on historical data. Computer-basedalerts and records also speed response time.

Using system-recorded data, researchers can quantitatively judge thesuccess of experimental intervention strategies that have beenimplemented at the subject's facility. As well, governmental agenciescan measure quality of care in regulated facilities. The spatialmonitoring component of the system can be especially useful for researchaddressing the influence of facility design on behavior.

As an example and not by way of limitation, an electronic scale havingan embedded transmitter can be provided in a subject's living space.When the subject stands upon the scale, the measurement is transmittedby the scale to the networked computer for chronological identifierassociation. The scale can be hard-wired to the network or its locationin the room can be fixed.

The system receives data from the spatial monitoring apparatus toindicate that Subject A is located in the rest room of Subject A'spersonal living space. Combining these data into a data record, thesystem can thereby determine that the scale sensors are weighing SubjectA. This determination can be accurately made even if another monitoredsubject is contemporaneously present in Subject A's living space. Bytriangulating data received from the unique personal transmitter devicesof the spatial monitoring apparatus, the system can discern that SubjectA is located in the area of the room where the scale is also located.

Minor variations in subject parameters can be set to be recorded but nottrigger alerts. For example, day-to-day fluctuations in body weight arenormal, due to water retention, variations in meal size or heavierattire. If weight continues to fluctuate or continues in a relativelysteady trend, an alert can then be transmitted to a health professionalthat the subject is gaining or losing weight, as the case may be.

In contrast, an elevation in a subject's body temperature is a lessnormal occurrence and is generally significant enough to warrantcaregiver notification or attention. As described, the system candiscriminate between health-related parameter departures and normaldeviations flowing from everyday activities, such as exercise or otherstrenuous physical activity.

Similarly, detection of an increase in subject pulse rate can be set tocause the system to transmit a warning to a caregiver. However, an alertwill not be generated when the pulse anomaly occurs during the time ofday in which the subject exercises. Acting dynamically, the systemdiscriminates between recurring exercise periods and isolated instancesof strenuous activity.

The system can also monitor activities to detect temporal discrepanciesin subject routine. For example, a subject who becomes violently illmight make several bathroom visits in a short time period. While thefirst visit violates no parameter boundary, the system detects therepetitive visits. Because of both the predetermined parameter settingsand baseline data, the system detects a physical or behavioralirregularity—multiple trips to the rest room in an abnormally shortperiod of time—and signals an appropriate party for investigation orother response.

A person skilled in the art will be able to practice the presentinvention in view of the present description, where numerous detailshave been set forth in order to provide a more thorough understanding ofthe invention. In other instances, well-known features have not beendescribed in detail in order not to obscure unnecessarily the invention.

Having described and illustrated the principles of the invention invarious embodiments thereof, it should be apparent that the inventioncan be modified in arrangement and detail without departing from suchprinciples. All modifications and variations are claimed coming withinthe spirit and scope of the following claims.

What is claimed is:
 1. A system for monitoring frequency and intensityof movement by a subject during sleep, comprising: a sleep structurehaving a sleeping surface upon which the subject rests; a plurality ofz-axis force sensors distributed about and coupled to the sleepstructure, each distributed force sensor being operative to develop apotential corresponding to an application of force applied to the sleepstructure in the z-axis direction by the subject and to communicate thepotential as a data signal; a comparator operative to compare datasignals from the sensors to discriminate among x-, y- and z-axismovements of the subject while upon the sleeping surface; and a datastorage device for storing a plurality of data signals.
 2. A method formonitoring frequency and intensity of movement by a recumbent subject,comprising: providing a sleep structure having a sleeping surface uponwhich the subject rests; providing a plurality of z-axis force sensorscoupled to the sleep structure, each member of the plurality of forcesensors being operative to develop a potential corresponding to anapplication of force by the subject to the sleep structure andtransmitted through the sleep structure to that member, the plurality offorce sensors being spatially distributed such that a load applieddownward on the sleeping surface is differentially sensed by each memberof the plurality of z-axis force sensors; differentially sensing by eachof the plurality of z-axis force sensors changes in force, the changesin force corresponding to movement of the subject upon the surface in adirection selected from the group consisting of: x-axis, y-axis, z-axisand x-axis, and z-axis and y-axis; providing the potentials, togetherwith chronological identifiers associated therewith, as movement data toa data analysis means; and analyzing the movement data.
 3. The method ofclaim 2, wherein analyzing the data includes determining trend datausing the stored signals and associated chronological identifiers. 4.The method of claim 3, wherein analyzing the data further includesproducing a histogram using the stored signals and associatedchronological identifiers.
 5. The method of claim 2, wherein analyzingthe data includes using potentials from the plurality of force sensorsto discriminate among x-, y- and z-axis movement of the subject whileupon the surface.
 6. A movement monitoring system suitable to monitor asubject recumbent on resting apparatus, comprising: a resting apparatus;an x-axis force sensor coupled to the resting apparatus and positionedto generate potentials corresponding to applications of x-axis force onthe apparatus; a y-axis force sensor coupled to the resting apparatusand positioned to generate potentials corresponding to applications ofy-axis force on the apparatus; a z-axis force sensor coupled to theresting apparatus and positioned to generate potentials corresponding toapplications of z-axis force on the apparatus; a personal trackingsubsystem configured to determine a subject identity from a detectedidentity signal corresponding to subject identity; a processor having adata storage device coupled thereto; and a data analyzer operative toassociate the tracking signal with the potentials to form data records.7. A method for monitoring frequency and intensity of movement by arecumbent subject, comprising: providing a resting apparatus having asurface upon which the subject rests, said resting apparatus havingcoupled thereto: an x-axis force sensor coupled to the resting apparatusand positioned to generate potentials corresponding to applications ofx-axis force on the apparatus, a y-axis force sensor coupled to theresting apparatus and positioned to generate potentials corresponding toapplications of y-axis force on the apparatus, and a z-axis force sensorcoupled to the resting apparatus and positioned to generate potentialscorresponding to applications of z-axis force on the apparatus;differentially sensing by each of the plurality of force sensors changesin force in the respective x-, y-, and z-axis directions correspondingto movement of the subject upon the surface; providing the potentials,together with chronological identifiers associated therewith, asmovement data to a data analysis means; and analyzing the movement data.8. The method of claim 7, wherein analyzing the data includesdetermining trend data using the stored signals and associatedchronological identifiers.
 9. The method of claim 8, wherein analyzingthe data further includes producing a histogram using the stored signalsand associated chronological identifiers.
 10. The method of claim 7,wherein analyzing the data includes using potentials from the pluralityof force sensors to discriminate among x-, y- and z-axis movement of thesubject while upon the surface.